As a material which is excellent in the gas barrier property, transparency, flexibility and non-adsorptive property of chemical, a block copolymer of a vinyl aromatic compound such as styrene and isobutylene is conventionally known and a production method thereof was also proposed (Patent Document 6).
Further, in order to eliminate the defects in that the moldability is bad and the surface appearance is not good when molding by injection molding is conducted, it is known to form a composition with a polyolefin such as polypropylene and a softener such as paraffin oil (Patent Documents 1 and 2).
In addition, a vinyl aromatic polymer hydride obtained by hydrogenating the aromatic ring of a vinyl aromatic polymer such as polystyrene is known, and it is known that the vinyl aromatic polymer hydride can be used as an optical lens or an optical disk because the low birefringence property is excellent (Patent Document 3). On the other hand, it is known that a vinyl aromatic copolymer hydride excellent in the flexibility is obtained by hydrogenating a block copolymer of a vinyl aromatic compound and a conjugate diene compound (Patent Documents 4, 5, 7 and 8).